1. Field of the Invention
The present invention relates to a display apparatus, and more particularly to a display apparatus having photo sensor formed on a substrate on which pixel arrays are formed.
2. Description of the Related Art
In the information society at the present time, electronic display apparatuses are more important as information transmission media and various electronic display apparatuses are widely applied for industrial apparatus or home appliances. Such electronic display apparatuses continue to advance to have new appropriate functions for various demands of the information society.
In general, electronic display apparatuses display and transmit various pieces of information to users who utilize such information. That is, the electronic display apparatuses convert electronic information signals outputted from an electronic apparatus into light information signals recognized by users' vision.
The electronic display apparatuses are generally divided into emissive display apparatuses and non-emissive display apparatuses. The emissive display apparatuses display light information signals through emitting lights, and the non-emissive display apparatus displays the light information signals through reflection, a scattering or an interference. The emissive display apparatuses include a cathode ray tube (CRT), a plasma display panel apparatus (PDP), a light emitting diode (LED) and an electroluminescent display apparatus (ELD). The emissive display apparatuses are called as active display apparatuses. Also, the non-emissive display apparatuses, called as passive display apparatuses, include a liquid crystal display apparatus (LCD), an electrochemical display apparatus (ECD) and an electrophoretic image display apparatus (EPID).
As a technology of semiconductor has been developed, the demand for new electronic display apparatuses has been greatly increased, such as a flat panel display apparatus which has excellent characteristics, for example, a thin thickness, a light weight, a low driving voltage and a low power consumption. The flat panel display apparatuses can be manufactured using the rapidly improving semiconductor technology.
In the flat panel apparatuses, liquid crystal display apparatuses (LCD) have been widely utilized for various electronic apparatuses because the liquid crystal display apparatuses are thin, and have low power dissipation and high display qualities approximately identical to those of the cathode ray tube. Also, the liquid crystal display apparatus can operate under a low driving voltage and can be easily manufactured.
The liquid crystal display apparatuses are generally includes a transmissive type, a reflection type and transmissive and reflective type liquid crystal display apparatuses. The transmissive type liquid crystal display apparatus displays information by using an ambient light source. The reflection type liquid crystal display apparatus displays information by using ambient light. The transmissive and reflective type liquid crystal display apparatus displays information by using ambient light source in a dark place, and displays information by using ambient light in a bright place.
The electroluminescent display apparatus includes an organic electrodluminescent display apparatus and an inorganic electroluminescent display apparatus. The organic electroluminescent display apparatus has merits such as low power consumption, wide viewing angle, high-speed response, high contrast ratio, etc., so that researches on the organic electroluminescent display apparatus have been performed.
In the organic electroluminescent display apparatus, a cathode provides a light emitting part with electrons, and an anode provides the light emitting part with holes, so that the electrons combine with the holes to form excitons. The exitons drop to a ground state, so that a light is generated.
The organic electroluminescent display apparatus includes a passive matrix type display apparatus and active matrix type display apparatus. The active matrix type organic electroluminescent display apparatus has a plurality of organic electroluminescent devices. The organic electroluminescent devices corresponding to pixels are driven independently to display an image.
However, the organic electroluminescent display apparatus is one of the emissive display apparatuses, so that the organic electroluminescent display apparatus may not be formed in a reflective type. Thus, when an environmental light is bright, a visibility is deteriorated.
Further, the transmissive and reflective type liquid crystal display apparatus has a limit to display a high quality image because the transmissive and reflective type liquid crystal display apparatus may not determine an intensity of the environmental light by itself.